Velocity Anisotropy Of Two Deep Crystalline Samples
Using ultrasonic velocity measurements taken over a multiplicity of directions we show that samples exhibit weak to moderate anisotropy of seismic velocities. We further define the anisotropic geometry with high resolution scanning electron microscopy. Our data indicate that one sample, a granite...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Technical Report |
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Massachusetts Institute of Technology. Earth Resources Laboratory
2012
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| Online Access: | http://hdl.handle.net/1721.1/75149 |
| _version_ | 1811074687882493952 |
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| author | Mendelson, Jim Toksoz, M. N. |
| author2 | Massachusetts Institute of Technology. Earth Resources Laboratory |
| author_facet | Massachusetts Institute of Technology. Earth Resources Laboratory Mendelson, Jim Toksoz, M. N. |
| author_sort | Mendelson, Jim |
| collection | MIT |
| description | Using ultrasonic velocity measurements taken over a multiplicity of directions we show
that samples exhibit weak to moderate anisotropy of seismic velocities. We further
define the anisotropic geometry with high resolution scanning electron microscopy.
Our data indicate that one sample, a granite, is transversely anisotropic, and that the
presence of fine to moderately fine microcracks is the most important factor effecting
the velocities. We model the angular velocity dependence using 5 elastic constants
and show that all 9 observed velocities fit these predictions to within 0.1 km/s. We
are unable to obtain similar fits to a second sample, a mica-schist, in the same fashion.
SEM observations indicate this rock displays orthorhombic symmetry. We made
additional velocity measurements in order to calculate 9 elastic constants, and found
that the predicted angular velocity dependence agreed much better with our velocity
observations. |
| first_indexed | 2024-09-23T09:53:46Z |
| format | Technical Report |
| id | mit-1721.1/75149 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T09:53:46Z |
| publishDate | 2012 |
| publisher | Massachusetts Institute of Technology. Earth Resources Laboratory |
| record_format | dspace |
| spelling | mit-1721.1/751492019-04-10T18:05:03Z Velocity Anisotropy Of Two Deep Crystalline Samples Mendelson, Jim Toksoz, M. N. Massachusetts Institute of Technology. Earth Resources Laboratory Mendelson, Jim Toksoz, M. N. Using ultrasonic velocity measurements taken over a multiplicity of directions we show that samples exhibit weak to moderate anisotropy of seismic velocities. We further define the anisotropic geometry with high resolution scanning electron microscopy. Our data indicate that one sample, a granite, is transversely anisotropic, and that the presence of fine to moderately fine microcracks is the most important factor effecting the velocities. We model the angular velocity dependence using 5 elastic constants and show that all 9 observed velocities fit these predictions to within 0.1 km/s. We are unable to obtain similar fits to a second sample, a mica-schist, in the same fashion. SEM observations indicate this rock displays orthorhombic symmetry. We made additional velocity measurements in order to calculate 9 elastic constants, and found that the predicted angular velocity dependence agreed much better with our velocity observations. Massachusetts Institute of Technology. Full Waveform Acoustic Logging Consortium Ente nazionale per l'energia elettrica 2012-12-03T18:30:47Z 2012-12-03T18:30:47Z 1989 Technical Report http://hdl.handle.net/1721.1/75149 Earth Resources Laboratory Industry Consortia Annual Report;1989-13 application/pdf Massachusetts Institute of Technology. Earth Resources Laboratory |
| spellingShingle | Mendelson, Jim Toksoz, M. N. Velocity Anisotropy Of Two Deep Crystalline Samples |
| title | Velocity Anisotropy Of Two Deep Crystalline Samples |
| title_full | Velocity Anisotropy Of Two Deep Crystalline Samples |
| title_fullStr | Velocity Anisotropy Of Two Deep Crystalline Samples |
| title_full_unstemmed | Velocity Anisotropy Of Two Deep Crystalline Samples |
| title_short | Velocity Anisotropy Of Two Deep Crystalline Samples |
| title_sort | velocity anisotropy of two deep crystalline samples |
| url | http://hdl.handle.net/1721.1/75149 |
| work_keys_str_mv | AT mendelsonjim velocityanisotropyoftwodeepcrystallinesamples AT toksozmn velocityanisotropyoftwodeepcrystallinesamples |